Objectives: The aim of this study was to determine antiretroviral drug resistance patterns in patients on long-term antiretroviral therapy presenting with OPC.

Methods: An exploratory survey was performed among HIV-infected patients on ART for minimum of 24 months presenting with OPC in Nairobi, Kenya. Type (pseudomembraneous or erythematous candidiasis, angular cheilitis) and previous episodes of OPC, CD4-cell counts, duration, regimen and adherence on ART were compared between patients with high (>1000copies/ml) and low HIV-RNA levels. Genotypic resistance testing was performed on those with high viral loads.

HIV genotyping performed in 22 of the 28 patients showed that most (18/22) had drug resistance mutations of which 12/18 had Lamivudine-associated M184V mutation, 14/18 had TAMS and 16/18 had NNRTI mutations. One patient had major PI mutations.

Conclusion: Virological failure and drug resistance mutations including TAMs should be suspected in patients on long-term ART that present with pseudomembraneous candidiasis. We propose to include recurrent OPC in the WHO clinical criteria for ART failure as well as to establish clinical training sessions to build competences among health care providers.

It is unknown is whether OPC indicates early virological failure or mostly occurs in patients with resistant virus with limited effective treatment options. The aim of this study was to determine antiretroviral drug resistance patterns in patients on long-term ART presenting with OPC. The study was carried out in Nairobi East district in Kenya, where over 20,000 ART treated patients seek regular consultations [1212. Kenya Health information system (2014).].

Methods

This study received approval from the Kenyatta National Hospital/University of Nairobi Ethics and Research Committee (approval number KNH-ERC/A/474) and from the Ministry of Public Health and Sanitation (Ref. No. MPHS/IB/1/14 Vol. III. This trial was registered in the Netherlands Trial Register (http://www.trialregister.nl, NTR2627).

First-line ART treatment consisted of Lamivudine and AZT or d4T or Tenofovir disoproxil fumarate (Tenofovir) in combination with either Nevirapine or Efavirenz. Patients on first line treatment included those who had received prior antiretroviral treatment such as prevention of mother to child transmission of HIV infection treatment (PMTCT) and intra-class ART switch for instance from AZT to TDF. In case of second-line treatment, PIs were part of the regimen that includes two NRTIs as well. Patients were included if all criteria a) confirmed HIV infection b) presently on ART and for a minimum of 24 months c) confirmed OPC d) not currently on anti-mycobacterium drugs, were fulfilled and informed consent was signed for. All patients were taking cotrimoxazole.

NRTI resistance mutations considered were Lamivudine associated M184V mutation, TAMs (defined as various combinations of mutations at positions 41,67,70,210,215 and 219) and K65R mutation (which results in a four-fold decrease of Tenofovir susceptibility).

Statistical differences between dependent variables under low and high HIV-RNA plasma viral loads categories were analysed using SAS version 9.2 (SAS Institute, Cary, NC, USA) for frequencies using Fisher's exact test and for medians using Wilcoxon tests. The level of significance was set at 0.05.

Patients were categorized as having pseudomebraneous candidiasis if this lesion appeared alone or in combination with another type of OPC.

Results

A total 45 patients were evaluated, predominantly female (n=33).

Except for age, patients with low and high HIV-RNA levels were similar in sociodemographic characteristics, indicating that these variables did not influence HIV-RNA plasma levels (Table 1).

Analysis of clinical characteristics and OPC risk factors is presented in Table 2.

Table 2:

Analysis of clinical characteristics and OPC risk factors of 45 patients with high and low HIV-RNA plasma levels on chronic ART presenting with oropharyngeal candidiasis in Nairobi East district.

Table 2: Analysis of clinical characteristics and OPC risk factors of 45 patients with high and low HIV-RNA plasma levels on chronic ART presenting with oropharyngeal candidiasis in Nairobi East district.

Characteristics

HighHIV-RNA plasma levels (>1000 cp/ml)
n=28

LowHIV-RNA plasma levels
(<1000 cp/ml)
n=17

P value

Type of OPC

pseudomembraneous

26

2

<.0001

erythematous

1

13

angular cheilitis

1

2

Had OPC episodes in the past one year

16

3

0.0132

CD4 at OPC diagnosis (median)

74

521

<.0001

Viral loads at OPC diagnosis (median)

111,191

<20

<.0001

Years since HIV diagnosis (median)

6.5

6

0.15

Years on ART (median)

6

5

0.15

History of TB

19

8

0.2162

On current co-medications

9

3

0.69

Adherence to ART:

adheres to ART>95% (pill count)1

25

16

1.000

ART treatment interruptions2

12

3

0.1097

adheres to ART(knows ART dosage)

24

10

0.0721

1Patient having missed two or less ART doses per month.
2Patient having skipped more than one month between regimens.

Conclusions

Virological failure and resistance mutations including TAMs should be suspected in patients on long-term ART that present with pseudomembranous candidiasis. We propose to include recurrent OPC in the WHO clinical criteria for ART failure as well as to establish clinical training sessions to build competences among health care providers.

Acknowledgements

We thank all staff of participating health facilities, the participating patients and primary health care workers for their willingness to participate in this study. LNK also thanks the Kenya Ministry of Public Health and Sanitation for permission to carry out this study.

The authors declare that this manuscript is original, has not been published before and is not currently being considered for publication elsewhere. There are no other competing interests.

Authors' contributions

LNK, WJMVDS, TMAWM, NHJC and AVDV created the study design and participated in the discussions about the study design. LNK, AVDV and EOD participated in the field work. JM performed the statistical analysis. LNK, AVDV, WJMVDS, JM and FFS drafted the manuscript. All authors have read and approved the final manuscript.

Funding

The study was funded by a research grant from The Netherlands Organization for International Cooperation in Higher Education (NUFFIC, Grant nr: C&B-NFB-PHD.10/10) and Radboud University Nijmegen Medical Centre.